Transactions of the Illinois State Academy of Science.
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llinois State Academy of Science
FOURTEENTH ANNUAL MEETING
Southern Illinois State Normal University
April 29th and 30th, 1921
[Published by Authority of the State of Illinois |
TABLE OF CONTENTS
Officers and Committees for 19214922.
Past Officers of the Academy ..,.......*....
■ ■ • ' • V
Report of the Secretary . . * .
Minutes of the Foukteenth Annual Meeting..,.
Treasurer's Report . . . . -
Papers of General Interest: — Invitation Addresses;
Some Events in the Geological History of Southern Illinois: Stoart
Weller. University of Chicago...', -
The Geography of the Ozarks: Frank H. Colyer. Southern Illinois
State Normal University. Caxbondale ••*••••
Undeveloped Resources of Southern Illinois: R, B, Miller, State
Forester. Natural History Survey Division. Urbana..,..,
The Lore of the Southern Illinois Ozarks: Clarence Bonnell, Town-
ship High School. Harrisburg. . .
**»*•*»•*•»*•***■ + «
Papers on Biology and Agriculture:
Some Plants of the Bois Fort Indian Reservation and Vicinity in
Minnesota: Albert R Reagan. Kayenta* Arizona
A Trip Among the Bird Islands of the Pacific Coast of Washington:
Albert B. Reagan. Kayenta, Arizona
Preliminary Report of the Bog? of Northern Illinois: W. G* Water-
man, Northwestern University, Evanston. . ,
Note on Juvenile Leaves in Thuja Occidentals: W. G, Waterman.
Northwestern University, Evanston
A Preliminary Key to Some Forest Tree Roots: W. B. McDougall.
University of Illinois, Urbana . .
Forest Conditions in Alexander County, Illinois: R. B. Miller, State
Forester, Urbana, and Geo. D. Fuller. University of Chicago.*.*
Growth as Related to Specific Gravity and Size of Seed: Mary E*
Renick, Illinois State Normal University. Normal. . . . . .
A Metrical Study of a Thousand Moth Cocoons: E. R. Downing,
The Agricultural Significance of the Tight Clay Subsoil of Southern
Illinois: fL S. Smith. Agricultural College. University of Illinois,
Urbana, and F, A. Fisher. Farm Advisor. Wabash County. Illinois
The Plant Ecology of the Rock River Woodlands of Ogle County,
Illinois: H. De Forest, Universitv of Chicago. 1920
Papers on Geolocy and Geography:
New Species of Devonian Fossils from Western Illinois; T. E. Savage.
University of Illinois, Urbana 197
Work of the Illinois State Geological Survey: James H. Hance, Stale
Geological Survey. Urbana 207
The Glacial History of the Sangamon River Valley at Decatur and its
Bearing on the Reservoir Project: Morris M. Leighton, State
Geological Survey, Urbana 213
The Effects of Faults and Dikes in the Saline County Coal Field:
Clarence BonnelL Harrisburg Township High School, Harrisburg 219
PAPERS ON GEOLOGY AND GEOGRAPHY
NEW SPECIES OF DEVONIAN FOSSILS FROM
Prof. T. E. Savage, University of Illinois
The Devonian limestones of Rock Island County, Illi-
nois, were deposited in a basin that was connected north-
westward with the Arctic Ocean, and are said to belong to
the northern or Interior Continental province. They are
an eastward continuation of the Devonian limestones of
eastern Iowa, with which they entirely correspond. These
limestones in Iowa were described by Owen 1 in 1852 as
"The limestones along Cedar Valley 1 ", and he considered
them equivalent to the upper Helderberg (Onondaga) and
Hamilton formations of the New York section.
James Hall- in 1858 also referred the Devonian lime-
stones in Iowa to the upper Helderberg (Onondaga) and
In a report on the Geology of Iowa in 1870 White 8 as-
signed all of the Devonian limestones of Iowa to the
Hamilton formation, under which name the strata were
Three years later Hall and Whitfield* restudied the De-
vonian Limestones of Iowa and correlated the limestone
in the vicinity of Waterloo with the upper Helderberg
(Onondaga) ; the white limestone near Raymond with the
Schoharie; and the limestones at Waverly and Indepen-
dence with the Hamilton of New York.
In 1878 Calvin 5 referred the Devonian limestones in
eastern Iowa to the Hamilton formation.
Barris, 6 who had studied the Devonian limestones in the
vicinity of Davenport and Rock Island, reported one or
more unconformities in those beds and considered the up-
per limestones of that region equivalent to the Hamilton of
New York, and the earlier Devonian limestones to the up-
per Helderberg (Onondaga).
1 Owen, D. D., Rept. Geol, Surv. Wis., Iowa and Minn., pp. 77-89, 1852.
2 Hall, James., Geol. of Iowa, Vol. I. pt. I. pp. 81-88, 1858.
3 White. C. A., Geol. of Iowa, Vol. I, p. 109, 1870.
4 Han, James and Whitfield, R. P.. 23rd. Ann. Rept. of Regents of N. Y. State
Cabinet, pp. 223-226, 1873.
5 Calvin, Samuel. Am. Jour, of Science. 3rd ser. Vol. 15. pp. 460-ifi2.
6 Barris. James, Proc. Davenport, Acad, of Science, Vol. 2, pp. 2fil-2*>9 and
198 ILLINOIS STATE ACADEMY OF SCIENCE
In volume I. of the reports on the Geological Survey of
Illinois Worthen 7 referred the Devonian limestones of Rock
Island County, Illinois, to both the upper Helderberg
(Onondaga) and the Hamilton formations. In discussing
the Geology of northeastern Iowa in 1891 MaGee 8 con-
sidered the Devonian limestones as a unit and revived the
name "Cedar Valley limestones" applied by Owen to these
strata more than 40 years before. MaGee proposed to dis-
tinguish the lower, brecciated member of these limestones
as the "Fayette breccia" from the town of Fayette, Iowa,
where they are well exposed.
The same year Calvin 9 gave the name Gyroceras beds
to the strata a few feet in thickness lying immediately above
the brecciated limestones containing many Gyroceroid
In 1895 Norton 10 proposed the name Wapsipinicon lime-
stone for the Devonian strata included in the Fayette brec-
cia of MaGee, and the Gyroceras beds of Calvin, from the
Wapsipinicon River in eastern Iowa where these rocks
are well exposed. He restricted the name Cedar Valley
limestone to the more shaly and very fossiliferous strata,
that occur above the Gyroceras beds in eastern Iowa.
Norton 11 also divided the Wapsipinicon limestone into the
following members: Otis beds at the base; Kenwood
shale; Lower Davenport limestone, equivalent to the
Fayette breccia of MaGee; and Upper Davenport lime-
stone, corresponding to the Gyroceras beds of Calvin.
This classification has generally been followed by the Iowa
Geological survey. Weller 12 has considered the Wapsipini-
con limestone of Iowa in the main equivalent in time to the
later Hamilton of the New York section and the Cedar Val-
ley limestone about contemporaneous with the Portage
group of New York.
The writer 13 has recently correlated all of the Cedar Val-
ley and Wapsipinicon limestones of Iowa and Illinois about
7 Worthen, A. H.. Geo). Surv. of Illinois, Vol. 1, p. 120, 1866.
8 MaGee, W. J., Eleventh Ann. Rept. U. S. Geol. Surv., p. 319, 1891.
9 Calvin, Samuel, Am. Geologist, Vol. VII T, p. 142, 1891.
If! Norton, W. H., Iowa Geol. Surv., Vol. IV, p. 155, 1895.
11 Norton, \\\ H., Proe. Iowa Aead. of Science, Vol. I. pt. 4, pp. 22-24, 1893.
12 Weller, Stuart, Outlines of Geological History with Especial Reference to
North Am., p. 101, 1910.
13 Savage, T. E., Devonian Formations in Illinois, Am, Jour, of Science, 4th
Scr., Vol. 49, Mch., pp. 181 and 182, 1920.
PAPERS ON GEOLOGY AND GEOGRAPHY
with the Tully limestone of the New York section. The
Wapsipinicon and Cedar Valley limestones are both pre-
sent in Rock Island County, Illinois, and the following mem-
bers of the Wapsipinicon limestone are recognized in that
region: Otis beds; Lower Davenport limestone; and Up-
per Davenport limestone.
The Otis Beds outcrop on Campbell's Island in the Mis-
sissippi River above Moline, and a few low exposures oc-
cur in the Illinois bank of the River in that vicinity. This
is gray to dark non-magnesian limestone, commonly rather
fine grained, and somewhat irregularly bedded. The thick-
ness does not exceed 15 or 20 feet. It is succeeded in this
region by the Lower Davenport limestone without any
trace of the Kenwood Shale. The Lower Davenport mem-
ber consists of strongly brecciated nonfossiliferous lime-
stone, the fragments of which are gray to dark, fine
grained, and show fine laminations on weathered surfaces.
The matrix is also fine grained, but is somewhat lighter in
color. This brecciated limestone is exposed in the Govern-
ment Island at Rock Island, and is the horizon formerly
quarried in Rock Island and Moline. The Lower Daven-
port limestone is overlain in apparent conformity by the
Upper Davenport member which is composed of gray,
granular, subcrystalline limestone, in irregular layers
from a few to twelve inches or more in thickness, and con-
tains several fossils, among which Phillipsastrea billingsi,
Diplophyllum major, Schizophoria macfarlanei, Gypidula
comis, and several Cephalopod species are characteristic.
This member is well exposed in the vicinity of Sears and
CEDAR VALLEY LIMESTONE
The Cedar Valley limestones are commonly more shaly,
more evenly beaded, and more richly f ossilif erous than those
of the Wapsipinicon which they succeed without any sedi-
mentary break. They outcrop in the banks of Mill Creek,
and farther west along several of the creeks both east and
west of Andalusia. These limestones are commonly rather
thin bedded, shaly and obliquely jointed in the lower part.
200 ILLINOIS STATE ACADEMY OF SCIENCE
The Acervularia coral reef is near the middle, above which
the layers are mostly limestone or dolomite. The total
thickness of the formation is nearly 70 feet.
The general succession and relations of the Devonian
rocks in Rock Island county are shown in the following
Generalized section of the Devonian rocks in the vicinity
of Rock Island, Illinois:
CEDAR VALLEY LIMESTONE. Feet
10. Dolomite, yellowish-gray to brown, in layers 6 to 24 inches thick,
alternating with thinner partings of shale, containing many
stromatoporoids and other fossils. Exposed along the creeks
both east and west of Andalusia 20
9- Limestone, thin bedded, gray, with partings of shale, containing
many stromatoporoids 5 Stropheodonta demissa, Schizophoria
iowensis, Athyris fultonensis, Atrypa reticularis (large shells),
Gomphoceras cf. ajax, and other fossils. Exposed near the months
of a few streams near Andalusia * 4
8. Dolomite, yellowish-gray, in layers 12 inches or less, containing
Cystodictya hamiltonesis, Athyris fultonensis, Spirifer asper,
S. sebvaricosus, Cyrtina hamiltonensis, small shells of Atrypa
reticularis and other fossils, . , , * • . . . • 6
7. Limestone, the upper V/i feet the Acervularia davidsoni coral
reef. The lower part is an organic breccia which in places pro-
jects by intersecting vertical plates into the underlying layer.
Exposed in the bank of the river below Andalusia, and in the
bank of Mill Creek near the center of Section 25, T. 17 N,
R. 2 W. .•■• * '"••• 8
6. Limestone, impure, bluish-gray, crinoidal, thin bedded, con-
taining Cladopora iowensis, Megistocrinus latus, Ghonetes scitu-
lus, Leptostrophia perplana, Spirifer asper, S. iowensis, S« sub-
varicosus* Cyrtina umbonata, and other fossils. Exposed at the
most of the localities where the overlying coral reef outcrops 5
5. limestone, blue, argillaceous, fine grained, with very oblique and
prominent jointing. Containing Spirifer iowensis, S. subvaricosus,
Cyrtina umbonata, Atrypa aspera var. hystrix, and other fossils.
Exposed along Mill Creek; and in the quarries near Linwood
and Buff alo : in Iowa ..-•*•». ■ •' 20
4, Limestone, fine-grained, rather thin bedded, with shaly partings,
containing Acervularia profunda, Favosites alpenensis, Schizo-
phoria iowensis, Pentamerella dubia, Pro duct ell a subalata,
Spirifer asper, S. bimesialis, and S. iowensis. Exposed in the
quarries and ledges in Rock Island, Sears and Milan, 5
Upper Davenport Beds).
3. Limestone, hard, gray, in imperfect layers 6 to 24 inches thick,
containing Astraeospongia hamiltonensis, Chonophyllum^ cf.
magnificum, Diplophyllun major, Phillipsastrea billingsi,
Spirifer subundiferous, and other fossils, exposed near the rail-
road bridge across Mill Creek, and near the wagon bridges across
Rock River. This is the horizon formerly worked in the old
quarries in Milan and Rock Island . , . 8
PAPERS ON GEOLOGY AND GEOGRAPHY
Lower Davenport Beds.
2, Limestone, white to dark gray, fine grained, in layers J A to 3%
feet thicks with few fossils, in places finely laminated, usually
much fractured and breeeiated, with fragments 1 to 24 inches in
diameter- Exposed in the Cady quarries in East Moline, in the
the Government Island* in the south bank of Mississippi River
in Rock Island, and forms the bed rock in Rock River valley
between Milan and Sears — fossils few or none, . . .
1. Limestone, light to dark gray, fine grained, not brecciated. in
irregular layers, containing spherical concretions of chalcedonic
quartz, and numerous shells of Martinia subumbona. Exposed on
the east side of Campbell's Island above Moline. and in the east
bank of Mississippi River opposite the island
ZAPHRENTIS PUTILLA N. SP.
Plate I. Figures 3 and 4.
Description :— Corallum simple, conical straight or slightly curved, sub-cir-
cular in cross-section, diameter increasing gently and at a rather uniform rate
from the apex. Surface marked by rather distinct septal furrows, and by oc-
casional transverse wrinkle?, or ridges and depressions, which are usually
small: rim of calyx thin, very little oblique; the calyx moderately deep con*
tracted below, with a rather large fossula; major septa commonly about 24.
ranging from 20 to 30, depending on the size or age of the corallite. their
inner extremities nearly or quite reaching the center; alternating w r ith the
major septa are an equal number of low, secondary, septa which are some-
times scarcely more than septal ridges.
The dimensions of two individuals are: Length 20 to 30 mm., diameter of
calyx 10 to 14 mm.
This species differs from most species of Zaphrentis in its small size, the
slight, if any, curvature, and the very gradually expanding corallum. It lacks
the pseudecolumella or vesiculose central area of Stereolasma rectum Hall.
and Streptelasma strictum HalL with which it most nearly corresponds in
size. It is distinguished from Zaphrentis calcareforme in that the shorter septa
do not join the longer, and the latter are not united with the wall of the fossula.
Horizon and Locality: — Common in the Cedar Valley limestone along Mill
Creek, near Milan, where it occurs a few feet below the Acervularia coral reef,
DIPLOPHYLLUM? MAJOR N. SP.
Plate I, Figures 1 and 2.
Description: — Corallum compound, in rather dense masses 1 to 2 feet in
diameter. The corallites are cylindrical, more or less parallel, nearly con-
tiguous or separated from one another by a distance less than the width of
the corallites. not connected by prolongations of the epitheca, circular in cross
section, varying from 8 to 12 mm. in diameter; marked on the surface by
indistinct longitudinal lines resembling septal ridges, and also hy fine trans-
verse lines, and rather strong annulations and constrictions. The calyx is
moderately deep, septa about 40, more or less undulating, half of them longer
than the others and joined together irregularly at the center, or uniting near
the center, to form an inner ring or wall surrounding a small central area.
The alternate or secondary septa are shorter than the primary ones, and ex-
tend slightly more than half the distance from the periphery to the center; thf*
disseppiments are numerous, and the septa carinated in the outer zone through
which both sets of septa extend: a few disseppiments are present in the more
open, centra] zone penetrated only by the longer septa. A few of the corallites
— about 1 out of every 5 in the same corallum,— show a ?mall central area
about 1 millimeter in diameter surrounded by a distinct wall formed by the
202 ILLINOIS STATE ACADEMY OF SCIENCE
coalescence of the inner edges of the longer septa, the other four-fifths of
the corallites show no such central area, the inner edges of the longer septa
uniting Irregularly in the central part of the corallite without forming a defi-
Horizon and Locality: — Common in the upper part of the Wapsipinicon
limestone in the vicinity of Milan, where it is associated with Phillipsastrea
billingsi, Gypidula comis, and the eephalopods described on a later page of
RHIPIDOMELLA MINIMA N. SP.
Plate II, Figures 1 and 2.
Description: — Shell small, biconvex, length and width about equal, the
greatest width anterior to the middle; hinge line about equal to J4 the greatest
width of the shell; the cardinal extremities rounded. Ventral valve most convex
in the umbonal region from which the surface curves rather abruptly to the
cardinal margin, and more gently to the lateral and anterior margins; without
trace of mesial fold or sinus, beak small, extending only a short distance above
the hinge line; cardinal area small, concave, its margins sharply defined; del-
thyrium rather broadly triangular. Dorsal valve not quite so convex as the
ventral, the greatest convexity posterior to the middle from which the surface
slopes gently in all directions, the median portion of the valve depressed into
a distinct sinus which begins near the beak, and becomes stronger anteriorly
but is po'orly defined laterally; the beak is small, not incurved; cardinal area
very narrow, lying almost in the plane of the valve*
The surface of both valves marked by numerous radiating striae which begin
near the beak, and bifurcate 3 or 4 times before reaching the front margin
where about 3 are present in a distance of one millimeter. These striae are
strongest and subangular on the unbones, decreasing somewhat in size towards
the front, A few concentric lines of growth are present near the front and
The dimensions of the shell are; Length 8 to 11 millimeters, greatest width
8 to 11 millimeters, thickness 3 to 3,5 millimeters.
Remarks: — In the small size, and in the mesial sinus of the dorsal valve
this species resembles Rhipidomella jerseyensis described by Weller from the
Kinderhood of Illinois and Missouri. It differs from that form in its typically
smaller size, the more nearly circular outline, the more angular and stronger
striae on the unbones, and the few r er and coarser striae over the surface of the
shell, the more concave or arched cardinal area of the vertical valve, the less
compressed cardinal extremities, and the more rounded front margin which
is not emarginate.
From Rhipidomella dubia (Hall) it is distinguished by the broader posterior
portion, more circular outline, longer hinge line, and the presence of a mesial
sinus in the dorsal valve, and its absence in the ventral*
From R. tenuicosta Weller from the Kinderhook our species differs in hav-
ing coarser striae, and a more distinct mesial sinus in the dorsal valve.
Horizon and Locality: — Common in the Cedar Valley stage of the Devonian^
along Mill Creek, near Milan, where it occurs a few feet below the Acervularia
davidsoni coral reef.
PUGNOIDES SUBOVATA N. SP.
Plate II. Figures 5, 6 and 7,
Description: — Shell broadly subovate to subtrigonal in outline, width and
length about equal, the greatest width slightly anterior to the middle of the
shell. The dimensions of 6 individuals range as follows: Length 8 to 10 mm.,
width 8 to 10.5 mm., thickness 5 to 8 mm.
The ventral valve is less convex than the dorsal except at the front, the
posterolateral margins nearly straight, and meet at the beak at an angle of
nearly 90 degrees, the lateral and anterior margins rounded; the surface is
convex in the umbonal region-, curving abruptly to the posterolateral margins,
and less abruptly in the anterolateral portion. The beak is pointed, not greatly
PAPERS ON GEOLOGY AND GEOGRAPHY
produced beyond that of the dorsal valve, only slightly incurved, closely ap-
prised over the beak of the opposite valve so as to conceal the foramen;
mesial sinus obsolete in the posterior part of the shell, but becomes rather
broad and deep in the anterior portion where it is produced in a rather broad
linguiform extension that curves strongly towards the dorsal valve. The
anterior part of the shell bears low, rounded plications of which 3 to 5 are
depressed in the mesial sinus, on each side of which 3 weak ridges are visible
for a short distance on the antero-lateral slopes.
Dorsal valve more convex than the ventral, the greatest convexity along the
middle part, from which the surface curves rather steeply to the postero — and
antero — lateral margins, and much less strongly towards the front margin; a
broad, low, mesial fold appears in the posterior half of the shell, becoming well
defined, and distinctly elevated at the front where it receives the extension of
the opposite valve; near the front are a few low, rounded radiating ridges, 4
to 6 of which are elevated on the mesial fold which is well defined, and is
bordered on each side by 2 or 3 weaker ridges, none of which extend to the
middle of the valve.
Besides the short, low, rounded, radiating ridges and furrows, the surface is
marked by numerous fine concentric lines which are visible with a lens; a few
stronger lines of growth are also usually present.
Remarks: — This shell is easily distinguished from Pugnoides pugnu*. and
Pugnoides pugnus var. alta, in the weak and rounded character of the radiating
plications, in whirh characters it more closely agrees with forms like Pug*
noides ottumwa of the Ste, Genevieve limestone, of Mississippian age. It
differs from the latter species in being much shorter and thicker in proportion
to its length.
Horizon and Locality:— It occurs abundantly in the Cedar Valley limestone*
a few feet above the Acervularia davidsoni coral reef, about two miles east of
Andalusia, in Rock Island County, Illinois.
CRANAENA SUBOVATA N, SP,
Plate IL Figures 9 and 10.
Description; — Shell subovate to subtriangular in outline, longer than wide.
the greatest width anterior to the mid-length, the posterolateral margins
nearly straight, converging to the beak at an angle of about 75 degrees; an-
terolateral margins rather strongly and regularly rounded, front margin trun-
cate or nearly straight* The dimensions of a shell of about average size are:
Length of ventral pedicle valve 17 mm.; of dorsal valve. 14.5 mm., greatest
width 14 mm-, convexity 9.5 mm.
Surface of ventral valve arched along the meridian line from beak to front,
the greatest convexity slightly posterior to the middle where a faint depression
appears, and increases in prominence toward the anterior margin where it
forms a broad, shallow, poorly defined mesial sinus. In the posterior part of
the shell the transverse curvature is rather strongly convex, being inflected a
little toward the cardinal extremities; the curvature is more gentle on the
anterior and antero-lateral portions of the valve; the beak is truncated, not
strongly incurved, perforated with a moderately large foramen; delthyrium
concealed by the beak of the opposite valve*
Dorsal valve about as convex as the ventral, the greatest convexity posterior
to the middle, gently arched from the beak to the front margin; the transverse
convexity greatest in the posterior portion, the surface curving rather steeply
from the median line to the cardinal and lateral margins, and more gently over
the anterior and antero-lateral areas: no mesial fold or sinus present; beak
pointed, and incurved beneath that of the ventral valve.
The surface of both valves is marked by numerous, well defined concentric
lines of growth which vary in number, strength, and distribution in different
shells, Shell structure punctate.
204 ILLINOIS STATE ACADEMY OF SCIENCE
Remarks: — This species is more closely related to Cranaena iowensis, de-
scribed by Calvin from the Cedar Valley limestone in Fayette County, Iowa,
than to any other known species* At the type locality in Iowa the shells of
Cranaena iowensis are commonly much larger than the most of those belonging
to that genus at the Illinois locality from which our specimens were collected.
Besides the smaller size the shells of our species are much more triangular in
outline, the beaks more attenuate, and the greatest width of the shell much
farther anteriorly than in Cranaena iowensis. Associated with Cranaena subo-
vata are shells which in form resemble Cranaena iowensis, and are referred
to that species although they are much smaller in size.
Horizon, and Locality: — Abundant in the Cedar Valley limestone a few feet
above the Acervularia davidsoni coral reef, a short distance west of Andalusia,
in Rock Island County-
CRANAENA ELLIPTICA N. SP.
Plate II, Figures 3 and 4,
Description:— Associated with Cranaena subovata* and Cranaena iowensis
at the locality last mentioned are shells belonging to the genus Cranaena
which differ from either of the above mentioned species in their more elliptical
outline, the greatest width being at or posterior to the mid-length; the cardino*
lateral margins are straight, and form an angle of about 90 degrees at the
beak. An average individual has a length of 15 mm., a width of 14 mm, and
a thickness of 10 mm. The surface is marked by numerous, rather fine con-
centric lines near the front and lateral margins, the anterior margin is trun-
cated, and there is no trace of mesial fold or sinus. These shells have every
indication of being fully grown and it is proposed to designate them by the
name of Cranaena elliptica.
CRANAENA MAXIMA N. SP.
Plate IL Figure II.
Among the shells of the species of Cranaena above mentioned there are
occasionally found shells that rather closely resemble Cranaena iowensis
in outline, but are readily distinguished from any described species of the
genus by their very large size. The individual figured measured 40 mm.
long, 32 mm. wide, and 15 mm, thick. Such shells may be approximately
referred to as Cranaena maxima.
CYPRICARDINIA ORNATA N. SP.
Plate II, Figure 8.
Description: — -Shell small, subquadrate to rhombic-ovate in outline; hinge
line straight, about half the greatest length of the shell; beaks situated near
the anterior margin, directed forward, incurved so that they rise but slightly
above the hinge line. The right valve is rather strongly convex; the anterior
end short, concave immediately below the beaks, rounding to the basal margin
which is straight or very gently convex, and slightly indented a little anterior
to the middle. The postero-ventral extremity rounded, above which the pos-
terior margin is obliquely truncate, the surface is most convex in the umbonal
region from which it curves rather steeply to the front margin, and more gently
towards the hinge line; a shallow depression with poorly defined borders ap-
pears near the beak and extends obliquely over the somewhat flattened umbo
and on to near the middle of the basal margin* A rather prominent elevation
extends from the dorsal or posterior margin of the umbo obliquely backward,
with decreasing prominence to the postero-basal extremity of the valve; from
this elevation the surface curves rather steeply towards the dorsal margin where
the shell is somewhat flattened.
The surface of the valve is marked by prominent } somewhat unequal con-
centric lines, about 5 mm. apart. The concentric lines, and less distinctly the
separating furrows, are crossed by two sets of fine striae, one set of which ap-
PAPERS ON GEOLOGY AND GEOGRAPHY
pears to radiate from the beak, and the other set crosses the first with a curva-
ture that trends forward and downward from the vicinity of the beak, crossing
the first set at an angle somewhat less than 90 degrees.
The left valve was not seen.
The dimensions of the type are: Length 9 mm,, height 5 mm., thickness of
right valve 3 mm.
Remarks: — This shell is most nearly like Cypricardinia indenta Conrad, from
the Hamilton of New York and the East, from which it differs in the smaller
size, the greater height in proportion to the length, in the less extended postero-
ventral border, the shorter hinge line, and in the peculiar ornamentation of the
surface of the shell.
Horizon and Locality:* — It occurs in the Cedar Valley stage of the Devonian
near Andalusia, in Rock Island County, where it is associated with the species
of Cranaena above described.
POTERIOCERAS GIGANTEA N. SP.
Description: — Shell large, subelliptical to ovate in cross-section, somewhat
curved throughout, the curvature slight on the concave side, but rather strong
on the convex; the greatest curvature is a short distance posterior to the base
of the body chamber. The length of the preserved part of the shell is 18
inches, the diameter of the posterior end of the specimen is 2 inches, several
of the lower chambers having been lost* The length of the entire shell must
have exceeded 20 inches. The shell is somewhat flattened in the direction of
the curvature; the largest part of the shell is at the second septum posterior
to the body chamber where the greatest diameter is 7 inches and the smallest
diameter is nearly 4^2 inches. Posterior to this the greatest width decreases
rather uniformly at the rate of 2^4 inches in a distance of 6 inches* The
septa are moderately concave, the average width of the chambers in the larger
part of the shell is 3/5 of an inch, and the average width of the posterior 3
inches of the shell is 1/3 of an inch. The body chamber is 4j^ inches long,
and has a greatest width of 6^4 inches at the posterior end. Anteriorly the
width decreases slightly, being a little more than 5 inches at the place of
greatest constriction immediately below the aperture. The aperture is mostly
concealed, but it is produced somewhat in the direction of thg greatest diameter
of the shell. The size and position of the siphuncle are not clearly shown, and
the surface markings of the shell are unknown.
Remarks: — This form differs from every other species of the genus known
to the writer in its very large size. In shape it somewhat resembles Poterioceras
hyatti Whitfield, but the latter is much smaller, and is considerably wider in
proportion to its length. The relation of the greatest width and the greatest
curvature is also different from that of the species above described*
Formation and Locality: — Occurs in the upper part of the Wapsipinieon
limestone, a short distance above the strongly brecciated bed, in the old
quarry at Sears, near Rock Island, Illinois,
RHYTICERAS ORNATA N. SP.
Description: — Shell rather large, regularly expanding, loosely coiled in a
little more than two volutions; the greatest diameter is 10J4 inches; in the
internal cast the distance between the volutions in the middle portion is about
Y% inches, but the w r horls approach to about % inch apart towards the body
chamber. The transverse section is subcircular or slightly elliptical, the lateral
diameter being a little greater than the dorsi* ventral. The greatest diameter of
the whorl (cast) is slightly more than 2 J /i inches; the original shell was
doubtless 3 inches in diameter. The greater part of the body chamber is lack-
ing in our specimen, and the aperture can not be seen* The septa are smooth,
their concavity about equalling the depth of the chambers, which is about Y%
of an inch near the aperture of the shell, and about J4 i fl ch near the middle,
206 ILLINOIS STATE ACADEMY OF SCIENCE
the depth gradually decreasing from the aperture toward the apex, The
position of the siphuncle is not clearly shown in our specimen, but appears to
be small, and situated near the ventral side, not enlarged in the chambers
between the septa*
The surface is ornamented by a row of prominent nodes or spinous projec-
tions about one inch apart along each side, which also appear to mark the
position of transverse ridges. Traces of a third row of spines or of a longi-
tudinal ridge appear along the ventral margin of the shell. On the dorsal
surface of the outer whorl there are preserved in some places rather prominent
longitudinal lines or ridges % to Y% inches apart ; such longitudinal markings
probably covered the entire surface of the shell. Numerous fine lamellose lines
of growth, some of which appear to be stronger than others, are also conspic-
uous on the portions of the shell that are preserved.
Remarks: — In the surface ornamentation this form is readily distinguished
from any other known species of Rhyticeras* It differs from Rhyticeras cyclops
Hall in the more gradual enlargement of the whorls, the stronger transverse
ridges, more prominent nodes along the lateral and ventral margins, and in the
finer longitudinal surface markings. From Rhyticeras spinosum Hall it is
distinguished by the stronger longitudinal ornamentation, and less rapid ex-
pansion of the anterior part of the shell.
Formation and Locality: — This species occurs in the upper part of the
Wapsipinicon limestone where it is associated with Gypidula comis, Poteri-
oeeras gigantea.. and Rhyticeras barrisi, near the village of Sears, in Rock
Island County, Illinois.
EXPLANATION OF PLATES
Figures 1 and 2, Diplophyllum? major n t sp. Transverse section of two
corallites magnified a little more than two times; and view of a fragment of
corallum, natural size.
Figures 3 and 4, Zaphrentis put ilia n. sp. Longitudinal view showing
septal ridges; and transverse section of a corallite. Both one and one-half
times natural size,
Figures 1 and 2, Rhipidomella minima n. sp. Ventral and dorsal views
of the type specimen. A little more than twice natural size.
Figures 3 and 4. Cranaena elliptic a n, sp. Dorsal and ventral views of
the type; magnified about two times the natural size.
Figures 5, 6 and 7, Pugnoides subovata n, sp, Ventral, dorsal and front
views of a typical specimen. Twice natural size*
Figure 8. Cypricardinia ornata n. sp. View of the right valve of a nearly
entire specimen; enlarged a little more than two times.
Figures 9 and 10, Cranaena subovata n. sp. Ventral and dorsal views of the
type specimen. Enlarged two times.
Figure 11. Cranaena maxima n* sp. Dorsal view of a typical specimen.
About twice natural size.
Figure 1. PoterioceTas gigantea n. sp. Longitudinal view of the type
specimen. A little less than one-half natural size.
Figure 1. Rhyticeras ornata n, sp. View of one side of an exfoliated
specimen. About one-half natural size.